1. Field of the Invention
The invention relates to antitheft guards for ignition switches and, more particularly, to such a guard adapted to encircle the steering column and overlie the ignition switch.
2. Description of the Prior Art
For many years now it has been conventional in a highway vehicle such as an automobile or truck to position the ignition switch on the steering column intermediate the steering wheel and the dashboard. Typically, the ignition switch is disposed on the steering column facing toward the right-hand side of the vehicle where it is accessible readily to the operator's right hand. Various controls such as a turn signal lever, headlight dimming lever and so forth may be disposed on the steering column, spaced generally diametrically from the ignition switch and facing toward the left-hand side of the vehicle where the lever may be accessible to the operator's left hand.
In recent years, the ignition switch has served several functions: (1) a key-operated switch by which the electrical system of the vehicle may be energized so that the engine and other vehicle components may be operated; (2) a steering wheel lock so that once the key has been removed from the ignition switch the steering wheel cannot be turned; and (3) a transmission lock so that once the key has been removed from the ignition switch the transmission cannot be shifted from a wheel-locking gear. It is common knowledge that the ignition switch can be bypassed and, hence, the vehicle stolen, if access may be had to portions of the electrical circuitry usually disposed under the vehicle's hood and near the engine. That is, the first-mentioned protective feature of the ignition switch can be defeated without the use of a key, provided appropriate wires in the electrical circuitry can be connected around the switch. Clearly the value of the ignition switch as a theft-deterrent device is diminished because of this shortcoming.
The other functions of the ignition switch (the steering wheel lock and transmission lock) pose a more substantial deterrent to potential thieves. This is because even if the engine can be started without the use of a key, the vehicle still cannot be driven if the steering wheel cannot be turned and the transmission cannot be shifted out of a wheel-locking gear. Unfortunately, it has been discovered that the locking features of the ignition switch can be defeated with little trouble. One approach is to insert the blade end of a slender, strong screwdriver into the key slot and drive the screwdriver blade through the lock by impacting the screwdriver with a large hammer or other object. By this technique, either the pins in the lock are sheared or the lock simply fails structurally. In either case, the locking features of the ignition switch are overcome and the vehicle may be driven.
Others have attempted to overcome this obvious defect of key-operated ignition switches by providing a guard adapted to prevent unauthorized access to the ignition switch. In a typical prior art ignition switch guard, a specially formed housing made of heavy gauge sheet material overlies the ignition switch and conforms closely to the contour of the steering column where the housing engages the steering column. Hinged arcuate sections, a U-bolt, or a chain may be connected to the housing and extend around the steering column so that through the use of an appropriate locking device, the housing may be secured rigidly to the steering column.
Such guards theoretically are effective deterrents to potential thieves. In practice, prior guards suffer certain drawbacks which limit their effectiveness or application. One drawback of prior guards is their excessive complexity which tends to increase manufacturing expenses to the extent that consumer acceptance is unlikely. It is apparent that an ignition switch guard, however meritorious, is completely ineffective if it so expensive that it is never purchased and used. In a similar vein, certain prior guards are quite bulky and unattractive. Again, consumer acceptance is unlikely because of the obvious difficulty in maneuvering the guard into and out of position, as well as the detrimental effect on the vehicle's appearance.
Other drawbacks of certain prior ignition switch guards deal with the strength characteristics of the guards. In one case the protective guard only partially overlies the ignition switch so that access to the ignition switch may be had rather easily by deforming the ignition guard as by prying with a crowbar. Other types of ignition guards may completely overlie the ignition lock, but may have hinges or locking devices of inadequate strength. The result of any of these shortcomings is that the guard can be deformed mechanically to the point where unauthorized access to the ignition switch may be had rather readily.